Two California legislators have refused to attend a Tuesday luncheon hosted by California Governor Jerry Brown in Sacramento to honor Mexican President Enrique Peña Nieto–and are instead protesting the continued imprisonment of U.S. Marine Sgt Andrew Tahmooressi in Mexico on gun charges.

California Senator Joel Anderson has joined California Assemblyman Tim Donnelly–both Republicans–in declining Brown’s invitation. Tahmooressi was arrested by Mexican officials for crossing the border in possession of firearms over five months ago, and is being held in a Mexican federal penitentiary without bail.

Donnelly will be leading a protest outside the luncheon venue in support for the release of Sgt. Tahmooressi. A Facebook event set up for the protest currently lists over 500 as “going.”

In a letter addressed to Governor Brown, Donnelly stated, “I am writing to decline your luncheon invitation, and to express my deep disappointment that you would entertain the President of a nation that is holding an active-duty US Marine captive.” He went on to comment on Brown’s recent delegation to Mexico: “Instead of fighting for his [Tahmooressi’s] release, you spent your time pushing the same extreme environmental policies on Mexico that have destroyed California’s economy.”

California Senator Joel Anderson also released a statement regarding his refusal to attend Governor Brown’s luncheon with the Mexican President saying, “I decline this invitation in solidarity with my fellow San Diegan, Marine Sgt Andrew Tahmooressi, and join millions of Americans in calling for increased pressure on President Obama, Secretary Kerry, and Governor Brown to demand his release.”

A release from Governor Brown’s office stated that the Governor had extended an invitation to the Mexican President to come to California while Brown was in Mexico last month for California’s Trade and Investment Mission to Mexico.

Brown had said of the relationship with the Mexican President, “We can come together in many ways, we can deal with climate change–there’s no better place for sun and wind and geothermal than Mexico and California.”

Brown’s office touted Brown’s signing of a letter of intent “with Mexico’s Secretary of Labor and Social Welfare to help protect the rights of Mexican migrant workers in California.” It also highlighted the Governor’s signing of the California Dream Act, which benefits those brought to the country illegally as children and “allows top students who are on the path to citizenship to apply for college financial aid.”